1. Technical Field
The disclosure relates to electric light fixtures and, more particularly, to electric light fixtures using light emitting diodes (LEDs) and having a plurality of power input options. The disclosure particularly relates to LED light fixtures configured for use in public transportation facilities where lighting failures are more critical than other facilities and wherein maintenance tie and costs must be minimized. The disclosure also relates to light fixtures usable in public facilities which provide a plurality of power input options and wherein the normal-use light fixture may be used as part of an emergency lighting system drawing power from a battery backup system.
2. Background Information
Essentially all commercial and public buildings and facilities are required by applicable safety codes to have emergency lighting systems that operate during failures of normal utility power supplies. In the past, the emergency lighting systems used lighting sources separate from the normal lighting and each system had independent wiring runs, installation locations, and housings. Newer devices use a single lighting source for both systems. Applicable safety codes dictate the locations, brightnesses, operation, and testing of the emergency lighting systems. Periodic testing of such equipment is required and enforced by a government authority having jurisdiction over the facility.
Many high traffic areas of public transportation facilities are located underground and require light fixtures that operate 24 hours per day, seven days per week, fifty-two weeks per year. These light fixtures must be reliable, easy to replace when burned out, and must be energy efficient. Traditional lighting in public transportation facilities requires bulb changes and typically only provides for a single type of power input. Replacement light fixtures that are easier to maintain and more power efficient are desired by the owners and operators of these facilities. Light fixtures that provide installation flexibility are also desired because the fixtures are often being retrofit into an existing location.